An encoder is provided in the stage of an automation system, a semiconductor manufacturing apparatus, a display apparatus manufacturing, etc., so as to be used for measuring the movement position or distance of a transfer unit moving along the base of the stage.
The encoder is connected to a transfer unit so as to move along with the transfer unit. The encoder moves without contacting the base having the linear scale attached thereto to electromagnetically read the linear scale. Thus, the encoder measures the moving position or distance of the transfer unit.
Meanwhile, if the encoder is properly aligned with the linear scale, the measurement by the encoder of the moving position or distance measured is not erroneous because the encoder can properly read the linear scale.
However, if the encoder is not properly aligned with the linear scale, the measurement by the encoder of the moving position or distance measured is erroneous because the encoder cannot properly read the linear scale.
Conventionally, there has been no structure for properly aligning the encoder with the linear scale. Hence, it has been difficult to properly align the encoder with the linear scale, and even realizing the misalignment of the encoder with the linear scale during operation, it is difficult to correct it.
Accordingly, the productivity has been lowered working with the equipment employing the encoder such as the automation system, semiconductor manufacturing apparatus, or display manufacturing apparatus.